The term 'NARROW ZONE' can be broken down into two words, 'NARROW' and 'ZONE'. NARROW is defined as having little width or being limited in size or scope. A ZONE is an area or region that has specific characteristics or qualities. Therefore, the term 'NARROW ZONE' can be interpreted as an area or region that is limited in size or scope. The crossword solution for this term is 'BELT', which is a strip of material worn around the waist or body. This could be interpreted as a metaphor for a NARROW ZONE, as a BELT is a thin strip of material that is used to define a certain area.